The Fowler/Bowers XTA holemike sets of mechanical two and three point bore micrometers are now available with extended travel. The extended travel or "XT" is available on all heads between .080-12"/2-300mm. Operators are now able to measure larger ranges with a single bore micrometer without having to interchange the anvils and re-calibrate the gage. The Fowler/Bowers XTA series of internal micrometers are one of the most popular brands of bore micrometers and is known for great quality.